Frozen Mountain and Void Station are both pretty fun to play on, Tinted Caverns only slightly less so due to a somewhat abrupt S-turn with a hazard that's hard to read.
Square Stadium looks a little boring but otherwise plays perfectly fine.
Egg Volcano looks like it's trying too hard to mimic Burning Bone Zone, and the spinning fire hazard is really hard to avoid.
Aerial Factory, Soda Beach, and Mushroom Top Swamp all have parts where it's almost impossible to tell where you're supposed to go, and the tracks themselves don't feel like they were built with Hard Speed in mind.
I'm not trying to be rude, of course. I'm just giving feedback on how I felt while playing the tracks.